title: Anatase TiO2 nanorod-decoration for highly efficient photoenergy conversion.
abstract: In recent studies of inorganic materials for energy applications, surface modification processes have been shown to be among the most effective methods to enhance the performance of devices. Here, we demonstrate a facile nano-decoration method which is generally applicable to anatase TiO2 nanostructures, as well as a nano-decorated hierarchical TiO2 nanostructure which improves the energy conversion efficiency of a dye-sensitized solar cell (DSSC). Using a facile sol-gel method, 0-D, 1-D, and 2-D type anatase TiO2 nanostructures were decorated with 200 nm long anatase TiO2 nanorods to create various hierarchical nanostructures. A structural analysis reveals that the branched nanorod has a highly crystalline anatase phase with anisotropic growth in the [001] longitudinal direction. When one of the hierarchical structures, a chestnut bur-like nanostructure, was employed in a dye-sensitized solar cell as a scattering layer, offering increased dye-loading properties, preserving a sufficient level of light-scattering ability and preserving superior charge transport and recombination properties as well, the energy conversion efficiency of the cell improved by 19% (from 7.16% to 9.09%) compared to a cell with a 0-D TiO2 sphere as a scattering layer. This generally applicable anatase nanorod-decorating method offers potential applications in various energy-conversion applications, especially in DSSCs, quantum-dot solar cells, photoelectrochemical water-splitting devices, photocatalysis, and lithium ion batteries.
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, Seoul 151-744, Korea. kshongss@plaza.snu.ac.kr.
authors.forename: Dong Hoe
authors.initials: DH
authors.lastname: Kim
authors.forename: Won Mo
authors.initials: WM
authors.lastname: Seong
authors.forename: Ik Jae
authors.initials: IJ
authors.lastname: Park
authors.forename: Eun-Sang
authors.initials: ES
authors.lastname: Yoo
authors.forename: Seong Sik
authors.initials: SS
authors.lastname: Shin
authors.forename: Ju Seong
authors.initials: JS
authors.lastname: Kim
authors.forename: Hyun Suk
authors.initials: HS
authors.lastname: Jung
authors.forename: Sangwook
authors.initials: S
authors.lastname: Lee
authors.forename: Kug Sun
authors.initials: KS
authors.lastname: Hong
mesh_terms: D004396:Coloring Agents / Q000737:chemistry; D043942:Nanotubes / Q000737:chemistry*; D012993:Solar Energy; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; C009495:titanium dioxide; D014025:Titanium